Houston… we have hot water!
This is going to sound awful, but have you ever had the experience of being generally unenthusiastic about something that someone else is really enthusiastic about, only to later get really pumped about it yourself, later on? Sort of like when your best friend has a baby when you haven’t and she is completely over the moon about this kid who has completely taken over her life, and you … well, you just can’t get that excited about it. Then you have a kid of your own and suddenly you’re over the moon about your child and the whole world should stop what they’re doing and admire this unbelievably cute child you’ve created, the child who is in fact “The cutest baby on the planet.”
Well that’s the way I’ve always felt about solar thermal. SDHW or Solar Domestic Hot Water, refers to using the sun to heat the hot water you use for baths and washing in your home. If you follow the industry standard chart of the economic payback of renewable energy and efficiency that Bill Kemp created for our book “$mart Power”, you’ll realize that the first solar panel you put on your roof should actually be one to make hot water, not to make electricity. It isn’t as sexy, but it will cost you less money and offers a much faster payback. And with all the techniques Bill outlines in his book, it will also significantly reduce your carbon footprint on the planet. Solar thermal systems convert more sunlight to useful energy (60 – 90%) than solar electric (16 – 20%).
When we moved off-the-electricity grid 10 years ago I began an odyssey of learning that focused on electricity rather than hot water. I built a tracker, upgraded my panels, replaced a propane fridge, added more panels, built another tracker, added more panels, put up a wind turbine – all with the goal of having enough electricity. Once the wind turbine was up it was time to do what homeowners should do first and get my solar thermal system installed. I had been lazy and had been relying on propane for most of my hot water. I offset some propane with my “diversion” or “dump” load, which is a hot water tank that I put excess electricity into when my batteries are full. For someone living on the grid, it would make more sense to pump this excess electricity into the grid and get paid for it, but I don’t have that option.
As with every project I’ve taken on here at Sunflower Farm, retrofitting a house built in 1888 poses a unique challenge. Surprisingly they never anticipated photovoltaic panels or solar thermal. In fact, I’m sure they hadn’t even anticipated electricity or indoor plumbing. What luxuries we’ve acquired in the western world! So installation involved welding together a stand for the panel to sit on the roof of the back porch, and then running various sets of plumbing throughout the house. Even after installing a new bathroom I admit to being marginally “plumbing challenged”, but it hasn’t stopped me yet. And then last week, we charged the system with propylene glycol so that it will produce hot water 12 months of the year, and the first sunny day it was ready to launch.
And I have to tell you, after installing solar panels for electricity, and putting up a wind turbine and watch it make electricity, making heat for your hot water is “the coolest thing ever!” Now I finally get it. All those times I stood in other peoples basements as they droned on about how it’s 20° outside but their hot water is 120° I just never got it. Yea, so what, big deal. But it is a big deal! It’s absolutely brilliant. You can install an appliance in your house that will reduce how much natural gas, propane or electricity you have to purchase with after tax dollars by 60%. And better yet, you’ll knock tons off your footprint on the planet. You’ll be reducing your C02 emissions by more than 2,000 lbs a year, and that’s significant.
And now I have a new activity to add to the time I spend watching my charge meter as the sun pours energy into my batteries, or the Amp meter on the wind turbine when the wind howls. Now I can go over to my solar thermal system and grab onto the thermosyphon loop and see just how hot the water is. I’m supposed to insulate this pipe, which I will do, just as soon as the novelty wears off. Hmm. Maybe I’ll just leave 6 inches exposed so I can keep checking it for a while! So what are you waiting for? Don’t you want to cut down on your energy bills? Don’t you want to reduce your carbon footprint? Don’t you want to be more energy independent? So get your own system installed and send us your photos of that “high” you get when you experience the glee of having the sun heat your water!